HR: 0800h
AN: PP31B-0414    [Abstracts]
TI: The Mg/Ca of Mixed Layer and Thermocline Dwelling Foraminifera From the Eastern Indian Ocean and Western Pacific
AU: * Gibbons, F T
EM: ferng@mit.edu
AF: Massachusetts Institute of Technology/Woods Hole Oceanographic Institution Joint Program in Oceanography, Mailstop 23 Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States
AU: Oppo, D W
EM: doppo@whoi.edu
AF: Department of Geology and Geophysics, Woods Hole Oceanographic Instituion, Mailstop 23 Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States
AU: Mohtadi, M
EM: mohtadi@uni-bremen.de
AF: Center for Marine Environmental Science (MARUM)and Geosciences Department University of Bremen, GEO 1, Raum R5120, Bremen, 28359, Germany
AU: Rosenthal, Y
EM: rosentha@imcs.marine.rutgers.edu
AF: Institute of Marine and Coastal Sciences and Department of Geological Sciences Rutgers State University of New Jersey, 71 Dudley Road, New Brunswick, NJ 08901, United States
AU: Linsley, B K
EM: blinsley@albany.edu
AF: Department of Earth and Atmospheric Sciences University at Albany-State University of New York, 1400 Washington Avenue, Albany, NY 12222, United States
AB: Using multi-core top material from the tropical Eastern Indian Ocean and Western Pacific Ocean, we evaluate the robustness of the Mg/Ca and temperature relationship in a variety of mixed layer (G. ruber (white, sensu stricto), G. sacculifer, and G. bulloides) and thermocline (N. dutertrei, P. obliquiloculata, and G. tumida) dwelling foraminifera species. Preliminary evidence suggests that the Mg/Ca ratio of N. dutertrei and P. obliquiloculata is lower in cores below 1,000m than above 1,000m, possibly indicating preferential dissolution of higher Mg-calcite. The Mg/Ca ratios of G. ruber and G. tumida do not exhibit the same depth dependence. Depth dependent Mg/Ca calibrations are created and tested against existing calibrations. Additionally, the potential for using the Mg/Ca derived temperatures of multiple species to reconstruct water column structure is evaluated using both modern hydrography and downcore records.
DE: 4924 Geochemical tracers
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting